Commit 8c28abed authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: arm64/chacha - remove the skcipher algorithms 



Since crypto/chacha.c now registers chacha20-$(ARCH), xchacha20-$(ARCH),
and xchacha12-$(ARCH) skcipher algorithms that use the architecture's
ChaCha and HChaCha library functions, individual architectures no longer
need to do the same.  Therefore, remove the redundant skcipher
algorithms and leave just the library functions.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 08820553

arch/arm64/crypto/Kconfig

+0 −7
Original line number Diff line number Diff line
@@ -189,16 +189,9 @@ config CRYPTO_AES_ARM64_NEON_BLK 
config CRYPTO_CHACHA20_NEON

	tristate

	depends on KERNEL_MODE_NEON

	select CRYPTO_SKCIPHER

	select CRYPTO_LIB_CHACHA_GENERIC

	select CRYPTO_ARCH_HAVE_LIB_CHACHA

	default CRYPTO_LIB_CHACHA_INTERNAL

	help

	  Length-preserving ciphers: ChaCha20, XChaCha20, and XChaCha12

	  stream cipher algorithms



	  Architecture: arm64 using:

	  - NEON (Advanced SIMD) extensions



config CRYPTO_AES_ARM64_BS

	tristate "Ciphers: AES, modes: ECB/CBC/CTR/XCTR/XTS modes (bit-sliced NEON)"

arch/arm64/crypto/chacha-neon-core.S

+1 −1
Original line number Diff line number Diff line 
/*

 * ChaCha/XChaCha NEON helper functions

 * ChaCha/HChaCha NEON helper functions

 *

 * Copyright (C) 2016-2018 Linaro, Ltd. <ard.biesheuvel@linaro.org>

 *

arch/arm64/crypto/chacha-neon-glue.c

+6 −138
Original line number Diff line number Diff line 
/*

 * ARM NEON and scalar accelerated ChaCha and XChaCha stream ciphers,

 * including ChaCha20 (RFC7539)

 * ChaCha and HChaCha functions (ARM64 optimized)

 *

 * Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>

 *
@@ -19,10 +18,8 @@ 
 * (at your option) any later version.

 */



#include <crypto/algapi.h>

#include <crypto/internal/chacha.h>

#include <crypto/chacha.h>

#include <crypto/internal/simd.h>

#include <crypto/internal/skcipher.h>

#include <linux/jump_label.h>

#include <linux/kernel.h>

#include <linux/module.h>
@@ -95,117 +92,6 @@ void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes, 
}

EXPORT_SYMBOL(chacha_crypt_arch);



static int chacha_neon_stream_xor(struct skcipher_request *req,

				  const struct chacha_ctx *ctx, const u8 *iv)

{

	struct skcipher_walk walk;

	u32 state[16];

	int err;



	err = skcipher_walk_virt(&walk, req, false);



	chacha_init(state, ctx->key, iv);



	while (walk.nbytes > 0) {

		unsigned int nbytes = walk.nbytes;



		if (nbytes < walk.total)

			nbytes = rounddown(nbytes, walk.stride);



		if (!static_branch_likely(&have_neon) ||

		    !crypto_simd_usable()) {

			chacha_crypt_generic(state, walk.dst.virt.addr,

					     walk.src.virt.addr, nbytes,

					     ctx->nrounds);

		} else {

			kernel_neon_begin();

			chacha_doneon(state, walk.dst.virt.addr,

				      walk.src.virt.addr, nbytes, ctx->nrounds);

			kernel_neon_end();

		}

		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);

	}



	return err;

}



static int chacha_neon(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);



	return chacha_neon_stream_xor(req, ctx, req->iv);

}



static int xchacha_neon(struct skcipher_request *req)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);

	struct chacha_ctx subctx;

	u32 state[16];

	u8 real_iv[16];



	chacha_init(state, ctx->key, req->iv);

	hchacha_block_arch(state, subctx.key, ctx->nrounds);

	subctx.nrounds = ctx->nrounds;



	memcpy(&real_iv[0], req->iv + 24, 8);

	memcpy(&real_iv[8], req->iv + 16, 8);

	return chacha_neon_stream_xor(req, &subctx, real_iv);

}



static struct skcipher_alg algs[] = {

	{

		.base.cra_name		= "chacha20",

		.base.cra_driver_name	= "chacha20-neon",

		.base.cra_priority	= 300,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct chacha_ctx),

		.base.cra_module	= THIS_MODULE,



		.min_keysize		= CHACHA_KEY_SIZE,

		.max_keysize		= CHACHA_KEY_SIZE,

		.ivsize			= CHACHA_IV_SIZE,

		.chunksize		= CHACHA_BLOCK_SIZE,

		.walksize		= 5 * CHACHA_BLOCK_SIZE,

		.setkey			= chacha20_setkey,

		.encrypt		= chacha_neon,

		.decrypt		= chacha_neon,

	}, {

		.base.cra_name		= "xchacha20",

		.base.cra_driver_name	= "xchacha20-neon",

		.base.cra_priority	= 300,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct chacha_ctx),

		.base.cra_module	= THIS_MODULE,



		.min_keysize		= CHACHA_KEY_SIZE,

		.max_keysize		= CHACHA_KEY_SIZE,

		.ivsize			= XCHACHA_IV_SIZE,

		.chunksize		= CHACHA_BLOCK_SIZE,

		.walksize		= 5 * CHACHA_BLOCK_SIZE,

		.setkey			= chacha20_setkey,

		.encrypt		= xchacha_neon,

		.decrypt		= xchacha_neon,

	}, {

		.base.cra_name		= "xchacha12",

		.base.cra_driver_name	= "xchacha12-neon",

		.base.cra_priority	= 300,

		.base.cra_blocksize	= 1,

		.base.cra_ctxsize	= sizeof(struct chacha_ctx),

		.base.cra_module	= THIS_MODULE,



		.min_keysize		= CHACHA_KEY_SIZE,

		.max_keysize		= CHACHA_KEY_SIZE,

		.ivsize			= XCHACHA_IV_SIZE,

		.chunksize		= CHACHA_BLOCK_SIZE,

		.walksize		= 5 * CHACHA_BLOCK_SIZE,

		.setkey			= chacha12_setkey,

		.encrypt		= xchacha_neon,

		.decrypt		= xchacha_neon,

	}

};



bool chacha_is_arch_optimized(void)

{

	return static_key_enabled(&have_neon);
@@ -214,30 +100,12 @@ EXPORT_SYMBOL(chacha_is_arch_optimized); 


static int __init chacha_simd_mod_init(void)

{

	if (!cpu_have_named_feature(ASIMD))

		return 0;



	if (cpu_have_named_feature(ASIMD))

		static_branch_enable(&have_neon);



	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?

		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;

}



static void __exit chacha_simd_mod_fini(void)

{

	if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && cpu_have_named_feature(ASIMD))

		crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));

	return 0;

}



arch_initcall(chacha_simd_mod_init);

module_exit(chacha_simd_mod_fini);



MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)");

MODULE_DESCRIPTION("ChaCha and HChaCha functions (ARM64 optimized)");

MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");

MODULE_LICENSE("GPL v2");
 
MODULE_ALIAS_CRYPTO("chacha20");

MODULE_ALIAS_CRYPTO("chacha20-neon");

MODULE_ALIAS_CRYPTO("xchacha20");

MODULE_ALIAS_CRYPTO("xchacha20-neon");

MODULE_ALIAS_CRYPTO("xchacha12");

MODULE_ALIAS_CRYPTO("xchacha12-neon");